Promising Chitosan-Coated Alginate-Tween 80 Nanoparticles as Rifampicin Coadministered Ascorbic Acid Delivery Carrier Against Mycobacterium tuberculosis

Synthesis and characterization of nano-biopolymer carriers loaded with clove (Syzygium aromaticum L.) extract as an anticancer agent: an in vitro study

The objective of this work was to design a new drug nanoparticle (NP) composed of chitosan/β-cyclodextrin/sodium tripolyphosphate/alginate (CS/βCD/TPP/AL) loaded with a clove extract (CE) for potential anticancer effects. The extract was prepared by two extraction methods: hydroalcoholic maceration (MAC) with 80% MeOH and supercritical fluid (SCF). The MACCE and SCFCE CE NPs had particle sizes of 71 nm and 20 nm, respectively with irregular spherical shapes. The nanocarriers achieved entrapment efficiencies of over 90%. MACCE-NPs and SCFCE-NPs released 18.35% and 10.12% of the extract after 6 h, respectively. Cell viability decreased to 54%, 7%, and 12% in HeLa, U87, and KB cell lines, respectively, after a 48-hour treatment with SCFCE-NPs and 75%, 8%, and 17% after treatment with MACCE-NPs, significantly reduced compared to the control. It is concluded that NPs containing CE exhibit a higher degree of toxicity due to better penetration into cells.

Quantification of rifampicin loaded into inhaled polymeric nanoparticles by reversed phase high-performance liquid chromatography in pulmonary nonphagocytic cellular uptake

Rifampicin is an antibiotic effective against both Gram-negative and Gram-positive bacteria and is commonly used as a first-line treatment for tuberculosis caused by Mycobacterium tuberculosis. In this study, a reversed-phase high-performance liquid chromatography method was developed and validated to assess rifampicin, either free or combined with ascorbic acid, loaded into chitosan/Tween 80-coated alginate nanoparticles. The method utilized a reversed-phase C18 Restek column with specific chromatographic conditions: a mobile phase of 60 : 40 ratios of methanol/buffer phosphate (pH 7.0), at a flow rate of 0.8 mL min-1, and an injection volume of 15 μL. rifampicin and the internal standard (rifamycin) had retention times of 4.0 and 2.5 min, respectively, and were detected at 334 nm. The method demonstrated the stability of stored samples after freezing-thawing cycles and specificity for rifampicin, even in the presence of degradation products from stress conditions. The high-performance liquid chromatography method was found to be specific, precise, robust, and sensitive. Results indicated that rifampicin accumulation and uptake kinetics varied based on cell type, formulation (free or loaded in nanoparticles), rifampicin concentration, and incubation time. Confocal fluorescence microscopy images supported these findings, showing isothiocyanate fluorescein nanoparticles distribution in different intracellular regions depending on the cell type used. The societal impact of this research lies in its potential to advance the treatment of respiratory infectious diseases, such as tuberculosis, through the development of more effective and specific drug delivery methods. By optimizing the way drugs, particularly rifampicin in this case, interact with lung cells, we aim to achieve greater treatment efficacy and alleviate the overall burden of disease. Furthermore, our study offers novel insights into the intracellular behavior of rifampin from polymeric nanoparticles, paving the way for personalized medicine approaches in the treatment of respiratory infections. This dual focus on social impact and innovation underscores our commitment to improving global health outcomes and addressing pressing public health challenges.

Progress in Treatment and Diagnostics of Infectious Disease with Polymers

In this era of advanced technology and innovation, infectious diseases still cause significant morbidity and mortality, which need to be addressed. Despite overwhelming success in the development of vaccines, transmittable diseases such as tuberculosis and AIDS remain unprotected, and the treatment is challenging due to frequent mutations of the pathogens. Formulations of new or existing drugs with polymeric materials have been explored as a promising new approach. Variations in shape, size, surface charge, internal morphology, and functionalization position polymer particles as a revolutionary material in healthcare. Here, an overview is provided of major diseases along with statistics on infection and death rates, focusing on polymer-based treatments and modes of action. Key issues are discussed in this review pertaining to current challenges and future perspectives.

Antimicrobial peptides grafted onto the surface of N-acetylcysteine-chitosan nanoparticles can revitalize drugs against clinical isolates of Mycobacterium tuberculosis

Tuberculosis is caused by Mycobacterium tuberculosis (MTB) and is the leading cause of death from infectious diseases in the World. The search for new antituberculosis drugs is a high priority, since several drug-resistant TB-strains have emerged. Many nanotechnology strategies are being explored to repurpose or revive drugs. An interesting approach is to graft antimicrobial peptides (AMPs) to antibiotic-loaded nanoparticles. The objective of the present work was to determine the anti-MTB activity of rifampicin-loaded N-acetylcysteine-chitosan-based nanoparticles (NPs), conjugated with the AMP Ctx(Ile21)-Ha; against clinical isolates (multi- and extensively-drug resistant) and the H37Rv strain. The modified chitosan and drug-loaded NPs were characterized with respect to their physicochemical stability and their antimycobacterial profile, which showed potent inhibition (MIC values <0.977 μg/mL) by the latter. Furthermore, their accumulation within macrophages and cytotoxicity were determined. To understand the possible mechanisms of action, an in silico study of the peptide against MTB membrane receptors was performed. The results presented herein demonstrate that antibiotic-loaded NPs grafted with an AMP can be a powerful tool for revitalizing drugs against multidrug-resistant M. tuberculosis strains, by launching multiple attacks against MTB. This approach could potentially serve as a novel treatment strategy for various long-term diseases requiring extended treatment periods.

Emamectin-sodium alginate nano-formulation based on charge attraction with highly improved systemic translocation and photolysis resistance

Nano pesticides offer an effective means of improving the bioavailability of pesticide due to their excellent solubility and wettability, superior foliar adhesion, and permeability to target insects. By using high-speed homogenization and ultrasonic dispersion technology, an emamectin-sodium alginate nano-formulation (EB@SA) with a particle size ranging from 30 to 50 nm was successfully fabricated using electrostatic self-assembly. The microscopic morphology and structure of EB@SA were further analyzed through transmission electron microscopy, dynamic light scattering, infrared spectroscopy, and 1H NMR. The photolysis resistance behavior of EB@SA demonstrated an improved anti-photolysis ability more than double that of conventional formulations while also exhibiting good sustained-release properties. Not only does EB@SA maintain the inherent insecticidal toxicity of emamectin benzoate (EB), but it also significantly prolongs its insecticidal duration. At a concentration of 20 mg/L, the lethality rate against Armyworms remains above 70 % over a period of 16 days compared to <50 % for general emamectin emulsifiable concentrate. Furthermore, EB@SA greatly enhances the systemic translocation of EB in corn plants by exhibiting favorable bidirectional systemic translocation characteristics. This research presents an efficient and environmentally friendly pesticide nano-formulation that can be effectively utilized for field pest control.

The Advancement and Obstacles in Improving the Stability of Nanocarriers for Precision Drug Delivery in the Field of Nanomedicine

Nanocarriers have emerged as a promising class of nanoscale materials in the fields of drug delivery and biomedical applications. Their unique properties, such as high surface area- tovolume ratios and enhanced permeability and retention effects, enable targeted delivery of therapeutic agents to specific tissues or cells. However, the inherent instability of nanocarriers poses significant challenges to their successful application. This review highlights the importance of nanocarrier stability in biomedical applications and its impact on biocompatibility, targeted drug delivery, long shelf life, drug delivery performance, therapeutic efficacy, reduced side effects, prolonged circulation time, and targeted delivery. Enhancing nanocarrier stability requires careful design, engineering, and optimization of physical and chemical parameters. Various strategies and cutting-edge techniques employed to improve nanocarrier stability are explored, with a focus on their applications in drug delivery. By understanding the advances and challenges in nanocarrier stability, this review aims to contribute to the development and implementation of nanocarrier- based therapies in clinical settings, advancing the field of nanomedicine.

Nano vs Resistant Tuberculosis: Taking the Lung Route

Tuberculosis (TB) is among the top 10 infectious diseases worldwide. It is categorized among the leading killer diseases that are the reason for the death of millions of people globally. Although a standardized treatment regimen is available, non-adherence to treatment has increased multi-drug resistance (MDR) and extensive drug-resistant (XDR) TB development. Another challenge is targeting the death of TB reservoirs in the alveoli via conventional treatment. TB Drug resistance may emerge as a futuristic restraint of TB with the scarcity of effective Anti-tubercular drugs. The paradigm change towards nano-targeted drug delivery systems is mostly due to the absence of effective therapy and increased TB infection recurrent episodes with MDR. The emerging field of nanotechnology gave an admirable opportunity to combat MDR and XDR via accurate diagnosis with effective treatment. The new strategies targeting the lung via the pulmonary route may overcome the new incidence of MDR and enhance patient compliance. Therefore, this review highlights the importance and recent research on pulmonary drug delivery with nanotechnology along with prevalence, the need for the development of nanotechnology, beneficial aspects of nanomedicine, safety concerns of nanocarriers, and clinical studies.

Advanced drug delivery and therapeutic strategies for tuberculosis treatment

Tuberculosis (TB) remains a significant global health challenge, necessitating innovative approaches for effective treatment. Conventional TB therapy encounters several limitations, including extended treatment duration, drug resistance, patient noncompliance, poor bioavailability, and suboptimal targeting. Advanced drug delivery strategies have emerged as a promising approach to address these challenges. They have the potential to enhance therapeutic outcomes and improve TB patient compliance by providing benefits such as multiple drug encapsulation, sustained release, targeted delivery, reduced dosing frequency, and minimal side effects. This review examines the current landscape of drug delivery strategies for effective TB management, specifically highlighting lipid nanoparticles, polymer nanoparticles, inorganic nanoparticles, emulsion-based systems, carbon nanotubes, graphene, and hydrogels as promising approaches. Furthermore, emerging therapeutic strategies like targeted therapy, long-acting therapeutics, extrapulmonary therapy, phototherapy, and immunotherapy are emphasized. The review also discusses the future trajectory and challenges of developing drug delivery systems for TB. In conclusion, nanomedicine has made substantial progress in addressing the challenges posed by conventional TB drugs. Moreover, by harnessing the unique targeting abilities, extended duration of action, and specificity of advanced therapeutics, innovative solutions are offered that have the potential to revolutionize TB therapy, thereby enhancing treatment outcomes and patient compliance.

Recent advances in cellulose, pectin, carrageenan and alginate-based oral drug delivery systems

Polymers-based drug delivery systems constitute one of the highly explored thrust areas in the field of the medicinal and pharmaceutical industries. In the past years, the properties of polymers have been modified in context to their solubility, release kinetics, targeted action site, absorption, and therapeutic efficacy. Despite the availability of diverse synthetic polymers for the bioavailability enhancement of drugs, the use of natural polymers is still highly recommended due to their easy availability, accessibility, and non-toxicity. The aim of the review is to provide the available literature of the last five years on oral drug delivery systems based on four natural polymers i.e., cellulose, pectin, carrageenan, and alginate in a concise and tabulated manner. In this review, most of the information is in tabulated form to provide easy accessibility to the reader. The data related to active pharmaceutical ingredients and supported components in different formulations of the mentioned polymers have been made available.

Metformin and curcumin co-encapsulated chitosan/alginate nanoparticles as effective oral carriers against pain-like behaviors in mice

Nanotechnology plays an integral role in multimodal analgesia. In this study, we co-encapsulated metformin (Met) and curcumin (Cur) into chitosan/alginate (CTS/ALG) nanoparticles (NPs) at their synergistic drug ratio by applying response surface methodology. The optimized Met-Cur-CTS/ALG-NPs were achieved with Pluronic® F-127 2.33% (w/v), Met 5.91 mg, and CTS:ALG mass ratio 0.05:1. The prepared Met-Cur-CTS/ALG-NPs had 243 nm particle size, -21.6 mV zeta potential, 32.6 and 44.2% Met and Cur encapsulations, 19.6 and 6.8% Met and Cur loading, respectively, and 2.9:1 Met:Cur mass ratio. Met-Cur-CTS/ALG-NPs displayed stability under simulated gastrointestinal (GI) fluid conditions and during storage. In vitro release study of Met-Cur-CTS/ALG-NPs in simulated GI fluids showed sustained release, with Met exhibiting Fickian diffusion and Cur demonstrating non-Fickian diffusion following the Korsmeyer-Peppas model. Met-Cur-CTS/ALG-NPs exhibited increased mucoadhesion and improved cellular uptake in Caco-2 cells. Additionally, Met-Cur-CTS/ALG-NPs exhibited better anti-inflammatory effects in lipopolysaccharide-stimulated RAW 264.7 macrophage and BV-2 microglial cells than the equivalent amount of the Met-Cur physical mixture, indicating a greater ability to modulate peripheral and central immune mechanisms of pain. In the mouse formalin-induced pain model, Met-Cur-CTS/ALG-NPs administered orally exhibited better attenuation of pain-like behaviors and proinflammatory cytokine release compared to the Met-Cur physical mixture. Furthermore, Met-Cur-CTS/ALG-NPs did not induce significant side effects in mice at therapeutic doses. Altogether, the present study establishes a CTS/ALG nano-delivery system for Met-Cur combination against pain with improved efficacy and safety.

Antihyperglycemic activity of nanoemulsion of brown algae (Sargassum sp.). Ethanol extract in glucose tolerance test in male mice

Nanoemulsion technology has been widely developed and applied to extracts of natural materials to enhance bioavailability and medicinal effects. This study aimed to determine the effectiveness of the Sargassum sp. ethanol extract nanoemulsions as an antihyperglycemic agent against fasting blood glucose levels in mice. The nanoemulsion formulation used Sargassum sp. extract and some additional ingredients, including chitosan, sodium tripolyphosphate, and tween 80. The antihyperglycemic test consisted of four groups, which were randomly selected. Treatment group (I) was given a nanoemulsion base without algae extract with a volume of 0.2mL/20gramBW; treatment group (II) was given glibenclamide at a dose of 0.52mg/20gramBW in 0.5% carboxymethylcellulose sodium (NaCMC) suspension with a volume of 0.2mL/20gramBW; treatment group (III) was given Sargassum sp. ethanol extract at a dose of 0.66mg/20 gramBW in 0.5% Na CMC suspension with a volume of 0.2mL/20gramBW; the treatment group (IV) was given formula of nanoemulsions of ethanol extract Sargassum sp with a volume of 0.2mL/20gramBW equivalent to a dose concentration Sargassum sp. ethanol extract of 0.66mg/20gramBW. The size of the nanoemulsion particles of the Sargassum sp. extract was 341.5-296.5nm with a zeta potential of 19.4-16.9mv. Treatment group (II) had the same antihyperglycemic effect as treatment group (IV). In contrast, treatment groups (I) and (III) had a relatively lower antihyperglycemic effect. This suggests that the Sargassum sp. extract nanoemulsion formula can be used as an alternative antihyperglycemic agent.

Alginate-Based Hydrogels and Scaffolds for Biomedical Applications

Alginate is a natural polymer of marine origin and, due to its exceptional properties, has great importance as an essential component for the preparation of hydrogels and scaffolds for biomedical applications. The design of biologically interactive hydrogels and scaffolds with advanced, expected and required properties are one of the key issues for successful outcomes in the healing of injured tissues. This review paper presents the multifunctional biomedical applications of alginate-based hydrogels and scaffolds in selected areas, highlighting the key effect of alginate and its influence on the essential properties of the selected biomedical applications. The first part covers scientific achievements for alginate in dermal tissue regeneration, drug delivery systems, cancer treatment, and antimicrobials. The second part is dedicated to our scientific results obtained for the research opus of hydrogel materials for scaffolds based on alginate in synergy with different materials (polymers and bioactive agents). Alginate has proved to be an exceptional polymer for combining with other naturally occurring and synthetic polymers, as well as loading bioactive therapeutic agents to achieve dermal, controlled drug delivery, cancer treatment, and antimicrobial purposes. Our research was based on combinations of alginate with gelatin, 2-hydroxyethyl methacrylate, apatite, graphene oxide and iron(III) oxide, as well as curcumin and resveratrol as bioactive agents. Important features of the prepared scaffolds, such as morphology, porosity, absorption capacity, hydrophilicity, mechanical properties, in vitro degradation, and in vitro and in vivo biocompatibility, have shown favorable properties for the aforementioned applications, and alginate has been an important link in achieving these properties. Alginate, as a component of these systems, proved to be an indispensable factor and played an excellent “role” in the optimal adjustment of the tested properties. This study provides valuable data and information for researchers and demonstrates the importance of the role of alginate as a biomaterial in the design of hydrogels and scaffolds that are powerful medical “tools” for biomedical applications.

Advances in inhaled antibiotics for management of respiratory tract infections

PURPOSE OF REVIEW

The incidence of bacterial respiratory tract infections is growing. In a context of increasing antibiotic resistance and lack of new classes of antibiotics, inhaled antibiotics emerge as a promising therapeutic strategy. Although they are generally used for cystic fibrosis, their use in other conditions is becoming more frequent, including no-cystic fibrosis bronchiectasis, pneumonia and mycobacterial infections.

RECENT FINDINGS

Inhaled antibiotics exert beneficial microbiological effects in bronchiectasis and chronic bronchial infection. In nosocomial and ventilator-associated pneumonia, aerosolized antibiotics improve cure rates and bacterial eradication. In refractory Mycobacterium avium complex infections, amikacin liposome inhalation suspension is more effective in achieving long-lasting sputum conversion. In relation to biological inhaled antibiotics (antimicrobial peptides, interfering RNA and bacteriophages), currently in development, there is no still enough evidence that support their use in clinical practice.

SUMMARY

The effective antimicrobiological activity of inhaled antibiotics, added to their potential to overcoming resistances to systemic antibiotics, make inhaled antibiotics a plausible alternative.

Gefitinib-loaded starch nanoparticles for battling lung cancer: Optimization by full factorial design and in vitro cytotoxicity evaluation

Lung cancer is the number one killer among all cancer types. For decades, clinicians have been using conventional chemotherapeutics, but they can't rely on them alone anymore, because they poison bad cells and good cells as well. Researchers exploited nanotechnology as a potential tool to develop a platform for drug delivery to improve therapeutic efficiency. A quality by design synthesis of gefitinib-loaded starch nanoparticles (Gef-StNPs) has emerged as an essential tool to study and optimize the factors included in their synthesis. Therefore, we applied design of experiment (DOE) tools to attain the essential knowledge for the synthesis of high-quality Gef-StNPs that can deliver and concentrate the gefitinib (Gef) at A549 cells, thereby improving therapeutic efficacy and minimizing adverse effects. The in vitro cytotoxicity after exposing the A549 human lung cancer cells to the optimized Gef-StNPs was found to be much higher than that of the pure Gef (IC₅₀ = 6.037 ± 0.24 and 21.65 ± 0.32 μg/mL, respectively). The optimized Gef-StNPs formula showed superiority over the pure Gef regarding the cellular uptake in A549 human cell line (3.976 ± 0.14 and 1.777 ± 0.1 μg/mL) and apoptotic population (77.14 ± 1.43 and 29.38 ± 1.11 %), respectively. The results elucidate why researchers have a voracious appetite for using natural biopolymers to combat lung cancer and paint an optimistic picture of their potential to be a promising tool in battling lung cancer.

A review of formulations and preclinical studies of inhaled rifampicin for its clinical translation

Inhaled drug delivery is a promising approach to achieving high lung drug concentrations to facilitate efficient treatment of tuberculosis (TB) and to reduce the overall duration of treatment. Rifampicin is a good candidate for delivery via the pulmonary route. There have been no clinical studies yet at relevant inhaled doses despite the numerous studies investigating its formulation and preclinical properties for pulmonary delivery. This review discusses the clinical implications of pulmonary drug delivery in TB treatment, the drug delivery systems reported for pulmonary delivery of rifampicin, animal models, and the animal studies on inhaled rifampicin formulations, and the research gaps hindering the transition from preclinical development to clinical investigation. A review of reports in the literature suggested there have been minimal attempts to test inhaled formulations of rifampicin in laboratory animals at relevant high doses and there is a lack of appropriate studies in animal models. Published studies have reported testing only low doses (≤ 20 mg/kg) of rifampicin, and none of the studies has investigated the safety of inhaled rifampicin after repeated administration. Preclinical evaluations of inhaled anti-TB drugs, such as rifampicin, should include high-dose formulations in preclinical models, determined based on allometric conversions, for relevant high-dose anti-TB therapy in humans.

Pulmonary drug delivery applications of natural polysaccharide polymer derived nano/micro-carrier systems: A review

Respiratory distress syndrome and pneumothorax are the foremost causes of death as a result of the changing lifestyle and increasing air pollution. Numerous approaches have been studied for the pulmonary delivery of drugs, proteins as well as peptides using meso/nanoparticles, nanocrystals, and liposomes. These nano/microcarrier systems (NMCs) loaded with drug provide better systemic as well as local action. Furthermore, natural polysaccharide-based polymers such as chitosan (CS), alginate (AG), hyaluronic acid, dextran, and cellulose are highly used for the preparation of nanoparticles and delivery of the drug into the pulmonary tract due to their advantageous properties such as low toxicity, high hydrophobicity, supplementary mucociliary clearance, mucoadhesivity, and biological efficacy. These properties ease the delivery of drugs onto the targeted site. Herein, recent advances in the natural polymer-derived NMCs have been reviewed for their transport and mechanism of action into the bronchiolar region as well as the respiratory region. Various physicochemical properties such as surface charge, size of nanocarrier system, surface modifications, and toxicological effects of these nanocarriers in vitro and in vivo are elucidated as well. Furthermore, challenges faced for the preparation of a model NMCs for pulmonary drug delivery are also discoursed.

Preparation of a pH‐responsive chitosan‐montmorillonite‐nitrogen‐doped carbon quantum dots nanocarrier for attenuating doxorubicin limitations in cancer therapy

Despite its widespread usage as a chemotherapy drug in cancer treatment, doxorubicin (DOX) has limitations such as short in vivo circulation time, low solubility, and poor permeability. In this regard, a pH‐responsive chitosan (CS)‐ montmorillonite (MMT)‐ nitrogen‐doped carbon quantum dots (NCQDs) nanocomposite was first developed, loaded with DOX, and then incorporated into a double emulsion to further develop the sustained release. The incorporated NCQDs into the CS‐MMT hydrogel exhibited enhanced loading and entrapment efficiencies. The presence of NCQDs nanoparticles in the CS‐MMT hydrogel also resulted in an extended pH‐responsive release of DOX over a period of 96 h compared to that of CS‐MMT‐DOX nanocarriers at pH 5.4. Based on the Korsmeyer‐Peppas model, there was a controlled DOX release at pH 5.4, while no diffusion was observed at pH 7.4, indicating fewer side effects. MTT assay showed that the cytotoxicity of DOX‐loaded CS‐MMT‐NCQDs hydrogel nanocomposite was significantly higher than those of free DOX (p < 0.001) and CS‐MMT‐NCQDs (p < 0.001) on MCF‐7 cells. Flow cytometry results demonstrated that a higher apoptosis induction achieved after incorporating NCQDs nanoparticles into CS‐MMT‐DOX nanocarrier. These findings suggest that the DOX‐loaded nanocomposite is a promising candidate for the targeted treatment of cancer cells.

Dry Powder Comprised of Isoniazid-Loaded Nanoparticles of Hyaluronic Acid in Conjugation with Mannose-Anchored Chitosan for Macrophage-Targeted Pulmonary Administration in Tuberculosis

Marketed dosage forms fail to deliver anti-tubercular drugs directly to the lungs in pulmonary Tuberculosis (TB). Therefore, nanomediated isoniazid (INH)-loaded dry powder for inhalation (Nano-DPI) was developed for macrophage-targeted delivery in TB. Mannosylated chitosan (MC) and hyaluronic acid (HA) with an affinity for the surface mannose and CD44 receptors of macrophages were used in conjugation to prepare hybrid nanosuspension by ionic gelation method using cross-linker, sodium tri-polyphosphate (TPP) followed by freeze-drying to obtain a dry powder composed of nanoparticles (INH-MC/HA NPs). Nanoformulations were evaluated for aerodynamic characteristics, cytotoxicity, hemocompatibility, macrophage phenotype analysis, and immune regulation. Cellular uptake imaging was also conducted to evaluate the uptake of NPs. The nanopowders did not pose any significant toxicity to the cells, along with good compatibility with red blood cells (RBCs). The pro-inflammatory costimulatory markers were upregulated, demonstrating the activation of T-cell response. Moreover, the NPs did not show any tolerogenic effect on the macrophages. Furthermore, confocal imaging exhibited the translocation of NPs in the cells. Altogether, the findings present that nano-DPI was found to be a promising vehicle for targeting macrophages.

Characteristics of SARS-CoV2 that may be useful for nanoparticle pulmonary drug delivery

As a non-invasive method of local and systemic drug delivery, the administration of active pharmaceutical ingredients (APIs) via the pulmonary route represents an ideal approach for the therapeutic treatment of pulmonary diseases. The pulmonary route provides a number of advantages, including the rapid absorption which results from a high level of vascularisation over a large surface area and the successful avoidance of first-pass metabolism. Aerosolization of nanoparticles (NPs) is presently under extensive investigation and exhibits a high potential for targeted delivery of therapeutic agents for the treatment of a wide range of diseases. NPs need to possess specific characteristics to facilitate their transport along the pulmonary tract and appropriately overcome the barriers presented by the pulmonary system. The most challenging aspect of delivering NP-based drugs via the pulmonary route is developing colloidal systems with the optimal physicochemical parameters for inhalation. The physiochemical properties of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) have been investigated as a template for the synthesis of NPs to assist in the formulation of virus-like particles (VLPs) for pharmaceutical delivery, vaccine production and diagnosis assays.

Nano-based anti-tubercular drug delivery: an emerging paradigm for improved therapeutic intervention

Tuberculosis (TB) classified as one of the most fatal contagious diseases is of prime concern globally. Mycobacterium tuberculosis is the causative agent that ingresses within the host cells. The approved conventional regimen, though the only viable option available, is unfavorably impacting the quality of life of the affected individual. Despite newer antibiotics gaining light, there is an unending demand for more therapeutic alternatives. Therefore, substantial continuous endeavors are been undertaken to come up with novel strategies to curb the disease, the stepping stone being nanotechnology. This approach is instrumental in overcoming the anomalies associated with conventional therapy owing to their intriguing attributes and leads to optimization of the therapeutic effect to a certain extent. This review focusses on the different types of nanocarrier systems that are being currently explored by the researchers for the delivery of anti-tubercular drugs, the outcomes achieved by them, and their prospects.

Biodegradable polymers-based nanoparticles to enhance the antifungal efficacy of fluconazole against Candida albicans

BACKGROUND

Fluconazole (FLZ), a potent antifungal medication, is characterized by poor water solubility that reduced its antifungal efficacy.

OBJECTIVE

This study aimed to prepare FLZ-loaded polymeric nanoparticles (NPs) by using different polymers and techniques as a mean of enhancing the antifungal activity of FLZ.

METHODS

NP₁, NP₂, and NP₃ were prepared by the double emulsion/solvent evaporation method using PLGA, PCL, and PLA, respectively. The ionotropic pre-gelation technique was applied to prepare an alginate/chitosan-based formulation (NP₄). Particle size, zeta potential, encapsulation efficiency, and loading capacity were characterized. FT-IR spectra of FLZ, the polymers, and the prepared NPs were estimated. NP₄ was selected for further in-vitro release evaluation. The broth dilution method was used to assess the antifungal activity of NP₄ using a resistant clinical isolate of Candida albicans.

RESULTS

The double emulsion method produced smaller-sized particles (<390 nm) but with much lower encapsulation efficiency (< 12%). Alternatively, the ionic gelation method resulted in nanosized particles with a markedly higher encapsulation efficiency of about 40%. The FT-IR spectroscopy confirmed the loading of the FLZ molecules in the polymeric network of the prepared NPs. The release profile of NP₄ showed a burst initial release followed by a controlled pattern up to 24 hours with a higher percent released relative to the free FLZ suspension. NP₄ was able to reduce the value of MIC of FLZ by 20 times.

CONCLUSION

The antifungal activity of FLZ against C. albicans was enhanced markedly via its loading in the alginate/chitosan-based polymeric matrix of NP₄.

Nanoparticle-mediated pulmonary drug delivery: state of the art towards efficient treatment of recalcitrant respiratory tract bacterial infections

Recalcitrant respiratory tract infections caused by bacteria have emerged as one of the greatest health challenges worldwide. Aerosolized antimicrobial therapy is becoming increasingly attractive to combat such infections, as it allows targeted delivery of high drug concentrations to the infected organ while limiting systemic exposure. However, successful aerosolized antimicrobial therapy is still challenged by the diverse biological barriers in infected lungs. Nanoparticle-mediated pulmonary drug delivery is gaining increasing attention as a means to overcome the biological barriers and accomplish site-specific drug delivery by controlling release of the loaded drug(s) at the target site. With the aim to summarize emerging efforts in combating respiratory tract infections by using nanoparticle-mediated pulmonary delivery strategies, this review provides a brief introduction to the bacterial infection-related pulmonary diseases and the biological barriers for effective treatment of recalcitrant respiratory tract infections. This is followed by a summary of recent advances in design of inhalable nanoparticle-based drug delivery systems that overcome the biological barriers and increase drug bioavailability. Finally, challenges for the translation from exploratory laboratory research to clinical application are also discussed and potential solutions proposed.

Exploring the Toxicity, Lung Distribution, and Cellular Uptake of Rifampicin and Ascorbic Acid-Loaded Alginate Nanoparticles as Therapeutic Treatment of Lung Intracellular Infections

Nanotechnology is a very promising technological tool to combat health problems associated with the loss of effectiveness of currently used antibiotics. Previously, we developed a formulation consisting of a chitosan and tween 80-decorated alginate nanocarrier that encapsulates rifampicin and the antioxidant ascorbic acid (RIF/ASC), intended for the treatment of respiratory intracellular infections. Here, we investigated the effects of RIF/ASC-loaded NPs on the respiratory mucus and the pulmonary surfactant. In addition, we evaluated their cytotoxicity for lung cells in vitro, and their biodistribution on rat lungs in vivo after their intratracheal administration. Findings herein demonstrated that RIF/ASC-loaded NPs display a favorable lung biocompatibility profile and a uniform distribution throughout lung lobules. RIF/ASC-loaded NPs were mainly uptaken by lung macrophages, their primary target. In summary, findings show that our novel designed RIF/ASC NPs could be a suitable system for antibiotic lung administration with promising perspectives for the treatment of pulmonary intracellular infections.

An evaluation of tocotrienol ethosomes for transdermal delivery using Strat-M® membrane and excised human skin

Tocotrienol (TRF) ethosomes were developed and evaluated in vitro for potential transdermal delivery against melanoma. The optimised TRF ethosomal size ranged between 64.9 ± 2.2 nm to 79.6 ± 3.9 nm and zeta potential (ZP) between -53.3 mV to -62.0 ± 2.6 mV. Characterisation of the ethosomes by ATR-FTIR indicated the successful formation of TRF-ethosomes. Scanning electron microscopy (SEM) images demonstrated the spherical shape of ethosomes, and the entrapment efficiencies of all the formulations were above 66%. In vitro permeation studies using full-thickness human skin showed that the permeation of gamma-T3 from the TRF ethosomal formulations was significantly higher (p < 0.05) than from the control. The cumulative amount of gamma-T3 permeated from TRF ethosome after 48 hours was 1.03 ± 0.24 µg cm^-2 with a flux of 0.03 ± 0.01 µg cm^-2 h^-1. Furthermore, the flux of gamma-T3 across the Strat-M ^® and the epidermal membrane was significantly higher than that across full-thickness human skin (p < 0.05). In vitro cytotoxicity studies on HaCat cells showed significantly higher cell viability than the pure drug solution (p < 0.05). The enhanced skin permeation and high cell viability associated with this formulation suggest a promising carrier for transdermal delivery.

Alginate Nanoformulation: Influence of Process and Selected Variables

Nanocarriers are defined as structures and devices that are constructed using nanomaterials which add functionality to the encapsulants. Being small in size and having a customized surface, improved solubility and multi-functionality, it is envisaged that nanoparticles will continue to create new biomedical applications owing to their stability, solubility, and bioavailability, as well as controlled release of drugs. The type and physiochemical as well as morphological attributes of nanoparticles influence their interaction with living cells and determine the route of administration, clearance, as well as related toxic effects. Over the past decades, biodegradable polymers such as polysaccharides have drowned a great deal of attention in pharmaceutical industry with respect to designing of drug delivery systems. On this note, biodegradable polymeric nanocarrier is deemed to control the release of the drug, stabilize labile molecules from degradation and site-specific drug targeting, with the main aim of reducing the dosing frequency and prolonging the therapeutic outcomes. Thus, it is essential to select the appropriate biopolymer material, e.g., sodium alginate to formulate nanoparticles for controlled drug delivery. Alginate has attracted considerable interest in pharmaceutical and biomedical applications as a matrix material of nanocarriers due to its inherent biological properties, including good biocompatibility and biodegradability. Various techniques have been adopted to synthesize alginate nanoparticles in order to introduce more rational, coherent, efficient and cost-effective properties. This review highlights the most used and recent manufacturing techniques of alginate-based nanoparticulate delivery system, including emulsification/gelation complexation, layer-by-layer, spray drying, electrospray and electrospinning methods. Besides, the effects of the main processing and formulation parameters on alginate nanoparticles are also summarized.

Exploring Endolysin-Loaded Alginate-Chitosan Nanoparticles as Future Remedy for Staphylococcal Infections

Endolysins are a novel class of antibacterials with proven efficacy in combating various bacterial infections, in vitro and in vivo. LysMR-5, an endolysin derived from phage MR-5, demonstrated high lytic activity in our laboratory against multidrug-resistant S. aureus (MRSA) and S. epidermidis strains. However, endolysin and proteins in general are associated with instability and short in vivo half-life, consequently limiting their usage as pharmaceutical preparation to treat bacterial infections. Nanoencapsulation of endolysins could help to achieve better therapeutic outcome, by protecting the proteins from degradation, providing sustained release, thus could increase their stability, shelf life, and therapeutic efficacy. Hence, in this study, the feasibility of alginate-chitosan nanoparticles (Alg-Chi NPs) to serve as drug delivery platform for LysMR-5 was evaluated. LysMR-5-loaded nanoparticles were prepared by calcium ion-induced pre-gelation of alginate core and its complexation with chitosan. The formation of nanoparticles was confirmed on the basis of DLS, zeta potential, and electron microscopy imaging. The LysMR-5-loaded nanoparticles presented a hydrodynamic diameter of 276.5 ± 42, a PDI of 0.342 ± 0.02, a zeta potential - 25 mV, and an entrapment efficiency of 62 ± 3.1%. The potential ionic interaction between alginate, chitosan, and LysMR-5 was investigated by FT-IR and SEM-EDX analysis. Using scanning electron microscopy (SEM) and transmission electron microscopy (TEM), nano-sized particles with characteristic morphology were seen. Different antibacterial assays and SDS-PAGE analysis showed no change in endolysin's structural integrity and bioactivity after entrapment. A direct antibacterial effect of blank Alg-Chi Nps, showing enhanced bactericidal activity upon LysMR-5 loading, was observed against S. aureus. At physiological pH (7.2), the release profile of LysMR-5 from Alg-Chi NPs showed a biphasic release and followed a non-Fickian release mechanism. The biocompatible nature as revealed by cytocompatibility and hemocompatibility studies endorsed their use as drug delivery system for in vivo studies. Collectively, these results demonstrate the potential of Alg-Chi NPs as nano-delivery vehicle for endolysin LysMR-5 and other therapeutic proteins for their use in various biomedical applications.

Current Status of Alginate in Drug Delivery

Alginate is one of the natural polymers that are often used in drug- and protein-delivery systems. The use of alginate can provide several advantages including ease of preparation, biocompatibility, biodegradability, and nontoxicity. It can be applied to various routes of drug administration including targeted or localized drug-delivery systems. The development of alginates as a selected polymer in various delivery systems can be adjusted depending on the challenges that must be overcome by drug or proteins or the system itself. The increased effectiveness and safety of sodium alginate in the drug- or protein-delivery system are evidenced by changing the physicochemical characteristics of the drug or proteins. In this review, various routes of alginate-based drug or protein delivery, the effectivity of alginate in the stem cells, and cell encapsulation have been discussed. The recent advances in the in vivo alginate-based drug-delivery systems as well as their toxicities have also been reviewed.

Multi-functionalized nanocarriers targeting bacterial reservoirs to overcome challenges of multi drug-resistance

INTRODUCTION

Infectious diseases associated with intracellular bacteria such as Staphylococcus aureus, Salmonella typhimurium and Mycobacterium tuberculosis are important public health concern. Emergence of multi and extensively drug-resistant bacterial strains have made it even more obstinate to offset such infections. Bacteria residing within intracellular compartments provide additional barriers to effective treatment.

METHOD

Information provided in this review has been collected by accessing various electronic databases including Google scholar, Web of science, Scopus, and Nature index. Search was performed using keywords nanoparticles, intracellular targeting, multidrug resistance, Staphylococcus aureus; Salmonella typhimurium; Mycobacterium tuberculosis. Information gathered was categorized into three major sections as 'Intracellular targeting of Staphylococcus aureus, Intracellular targeting of Salmonella typhimurium and Intracellular targeting of Mycobacterium tuberculosis' using variety of nanocarrier systems.

RESULTS

Conventional management for infectious diseases typically comprises of long-term treatment with a combination of antibiotics, which may lead to side effects and decreased patient compliance. A wide range of multi-functionalized nanocarrier systems have been studied for delivery of drugs within cellular compartments where bacteria including Staphylococcus aureus, Salmonella typhimurium and Mycobacterium tuberculosis reside. Such carrier systems along with targeted delivery have been utilized for sustained and controlled delivery of drugs. These strategies have been found useful in overcoming the drawbacks of conventional treatments including multi-drug resistance.

CONCLUSION

Development of multi-functional nanocargoes encapsulating antibiotics that are proficient in targeting and releasing drug into infected reservoirs seems to be a promising strategy to circumvent the challenge of multidrug resistance. Graphical abstract.